Why Truck Camper need a air bag? Do I really need it?

My short answer is probably not. Air bags typically help pick up an overloaded truck to return it to a level (normal ) ride position. There are cheaper ways to do that by better utilizing the overload springs by using longer overload bumpers or other more engineered and expensive solutions.

I think you would be better to spend the money on upgraded shocks and a anti-sway bar. Our last truck was a 2004 Dodge Ram 3500 that we loaded a comparably heavy camper on. I did have airbags but mostly to help control the imbalance of weight due to the full wall slide. The truck did carry the load ok without them.

In any case you should have plenty of stock truck to load it and get it home to further evaluate.

Presuming dually.
If you have doubts, haul it home with nothing for suspension mods. Truck will handle it fine but might be squatting more than you like. Then decide what you need for the back end.

Thanks.

Yes, the pickup is a dually

So, airbags are for balance between left and right?

Air bags can be for left/right balance but are usually primarily to allow you to adjust the stiffness of your suspension. I have them on my dually, I just dial up the pressure when loaded and turn it down when empty, no need to drive around getting jarred by permanently-stiff springs.

We have the 2014 Ram dually. Just added upper Stableloads and Timbrens on back. Works great. No need for airbags.
Hope you have/are getting Torklift tiedowns.

Personally would not want air bags anymore. I added upper Torklift stable loads on my ram which helped a lot with squat. Might add a swaybar. TC is over 4000 wet.

Your truck and camper will probably be fine.
It only needs air bags if the camper weight makes the rear end sag too much. When that happens the front headlights will point upward too much and at night it will blind other oncoming drivers.

Ram and chevy have stiffer springs than Fords - it's usually the Fords the sag over the rear axle. Your truck should be fine.

I have found the air bags just introduce more sway into the ride. Like others have said your money is better spent on a sway bar, overload stop extenders, and some good shocks.
But I bet your truck hauls it pretty good in stock trim.

Bags should help with the side-to-side sway.

Air bags will increase sway go with Timbrens first and then add a sway bar if necessary.